// Copyright 2015 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef V8_COMPILER_ALL_NODES_H_
#define V8_COMPILER_ALL_NODES_H_

#include "src/compiler/node.h"
#include "src/zone/zone-containers.h"

namespace v8 {
namespace internal {
    namespace compiler {

        // A helper utility that traverses the graph and gathers all nodes reachable
        // from end.
        class AllNodes {
        public:
            // Constructor. Traverses the graph and builds the {reachable} set of nodes
            // reachable from {end}. When {only_inputs} is true, find the nodes
            // reachable through input edges; these are all live nodes.
            AllNodes(Zone* local_zone, Node* end, const Graph* graph,
                bool only_inputs = true);
            // Constructor. Traverses the graph and builds the {reachable} set of nodes
            // reachable from the End node.
            AllNodes(Zone* local_zone, const Graph* graph, bool only_inputs = true);

            bool IsLive(const Node* node) const
            {
                CHECK(only_inputs_);
                return IsReachable(node);
            }

            bool IsReachable(const Node* node) const
            {
                if (!node)
                    return false;
                size_t id = node->id();
                return id < is_reachable_.size() && is_reachable_[id];
            }

            NodeVector reachable; // Nodes reachable from end.

        private:
            void Mark(Zone* local_zone, Node* end, const Graph* graph);

            BoolVector is_reachable_;
            const bool only_inputs_;
        };

    } // namespace compiler
} // namespace internal
} // namespace v8

#endif // V8_COMPILER_ALL_NODES_H_
